In wire-cut electric discharge machining, a table mounted with a workpiece is moved, while electric discharge is intermittently caused between a wire traveling from an upper nozzle to a lower nozzle and the workpiece disposed between the upper and lower nozzles, to thereby produce products having various shapes. In the case of cutting out a plurality of cores, each of which corresponds to a product or a cavity portion of the product, from a single workpiece, each time the cut-out machining of one core is completed, the workpiece is moved to the initial position for the cut-out machining associated with the next core. At this time, collision may occurs between the core and the lower nozzle to cause damages to the core or the lower nozzle. Conventionally, in order to obviate this awkward situation, the core cut out from the workpiece is removed from the workpiece prior to the movement of the workpiece toward the initial position for the next cut-out machining. For instance, the cut-out core is pulled out from the workpiece upwardly by the use of suction means such as magnet, suction pad, collet, etc., and is delivered to the outside of a region in which falling of the core is prohibited. Then, the core is disengaged form the suction means. Alternatively, the cut-out core is moved, with the core held within the workpiece by suction means, toward a safety position at which the core never collides with the nozzle or an arm which supports the nozzle even if falling of the core occurs. Then, the core is disengaged from the suction means, so as to permit the natural or gravitational falling of the core, and further the fallen core is delivered to the outside of the falling prohibition region by a belt conveyer or a delivering arm.
However, depending on the core shape, the core cannot be pulled out from the workpiece, or the natural falling of the core from the workpiece cannot be caused. For instance, the core which is taper-machined in a manner having its upper diameter smaller than its lower diameter cannot be pulled out from the workpiece upwardly. And, the natural falling of the core which is taper-machined to have its upper diameter larger than its lower diameter, from the workpiece, cannot be caused. Namely, according to the prior art, it is only possible to effect the core removal from the workpiece in either upward or downward direction. As a consequence, the core shape in the workpiece is restricted, resulting in such a drawback that cores formed into a trapezoidal shape in cross section and cores having a inverted trapezoidal sectional shape cannot be mixedly arranged in a single workpiece, and efficiency in utilizing the workpiece raw material is also lowered.